diff --git a/ext/cIGraph_operators.c b/ext/cIGraph_operators.c
new file mode 100644
index 0000000..7f73fff
--- /dev/null
+++ b/ext/cIGraph_operators.c
@@ -0,0 +1,9 @@
+#include "igraph.h"
+#include "ruby.h"
+#include "cIGraph.h"
+
+VALUE cIGraph_add_op(VALUE self, VALUE graph){
+
+  return Qnil;
+
+}
diff --git a/ext/cIGraph_selectors.c b/ext/cIGraph_selectors.c
new file mode 100644
index 0000000..12d4d1c
--- /dev/null
+++ b/ext/cIGraph_selectors.c
@@ -0,0 +1,93 @@
+#include "igraph.h"
+#include "ruby.h"
+#include "cIGraph.h"
+
+/* call-seq:
+ *   graph.vertices -> Array
+ *
+ * Returns an Array containing all the vertices in the graph. Also aliased
+ * to IGraph#all_vertices
+ *
+ * Example:
+ *
+ *  g = IGraph.new([1,2,3,4],true)
+ *  g.vertices #returns [1,2,3,4]
+ *
+ */
+VALUE cIGraph_all_v(VALUE self){
+  igraph_t *graph;  
+
+  Data_Get_Struct(self, igraph_t, graph);
+  return rb_funcall(rb_iv_get(self,"@object_ids"),rb_intern("keys"),0);
+
+}
+
+/* call-seq:
+ *   graph.adjacent_vertices(v,mode) -> Array
+ *
+ * Returns an Array containing all the vertices in the graph that are 
+ * adjacent to vertex v. mode decides the type of the neighborhood for 
+ * directed graphs. Possible values: IGRAPH_OUT, all vertices to which 
+ * there is a directed edge from vid. IGRAPH_IN, all vertices from which 
+ * there is a directed edge from vid. IGRAPH_ALL, all vertices to which 
+ * or from which there is a directed edge from/to vid. This parameter is 
+ * ignored for undirected graphs.
+ *
+ * Example:
+ *
+ *  g = IGraph.new([1,2,3,4],true)
+ *  g.adjacent_vertices(1,IGraph::ALL) #returns [2]
+ *
+ */
+VALUE cIGraph_adj_v(VALUE self, VALUE v, VALUE mode){
+
+  igraph_t *graph;  
+  igraph_integer_t pnode;
+  VALUE adjacent = rb_ary_new();
+  igraph_neimode_t pmode = NUM2INT(mode);  
+  igraph_vs_t vs;
+  igraph_vit_t vit;
+
+  Data_Get_Struct(self, igraph_t, graph);
+
+  pnode = cIGraph_get_vertex_id(self,v);
+
+  igraph_vs_adj(&vs,pnode,pmode);
+  igraph_vit_create(graph, vs, &vit);
+
+  while(!IGRAPH_VIT_END(vit)) {
+    rb_ary_push(adjacent,cIGraph_get_vertex_object(self,IGRAPH_VIT_GET(vit)));
+    IGRAPH_VIT_NEXT(vit);
+  }
+
+  igraph_vit_destroy(&vit);
+  igraph_vs_destroy(&vs);  
+
+  return adjacent;
+
+}
+
+VALUE cIGraph_nonadj_v(VALUE self, VALUE v, VALUE mode){
+
+  return Qnil;
+
+}
+
+VALUE cIGraph_all_e(VALUE self, VALUE mode){
+
+  return Qnil;
+
+}
+
+VALUE cIGraph_adj_e(VALUE self, VALUE v, VALUE mode){
+
+  return Qnil;
+
+}
+
+VALUE cIGraph_nonadj_e(VALUE self, VALUE v, VALUE mode){
+
+  return Qnil;
+
+}
+
diff --git a/test/tc_iterators.rb b/test/tc_iterators.rb
new file mode 100644
index 0000000..e8e29af
--- /dev/null
+++ b/test/tc_iterators.rb
@@ -0,0 +1,44 @@
+require 'test/unit'
+require 'igraph'
+
+class TestGraph < Test::Unit::TestCase
+  def test_each_vertex
+    graph = IGraph.new(['A','B','C','D'],true)
+    assert_nothing_raised do
+      graph.each_vertex do |v|
+      end
+    end
+    assert_nothing_raised do
+      graph.each do |v|
+      end
+    end
+  end
+
+  def test_each_edge
+    graph = IGraph.new(['A','B','C','D'],true)
+    assert_nothing_raised do
+      graph.each_edge(IGraph::EDGEORDER_ID) do |v,w|
+      end
+    end
+    assert_nothing_raised do
+      graph.each_edge_eid(IGraph::EDGEORDER_ID) do |v|
+      end
+    end   
+    edges = []
+    graph.each_edge(IGraph::EDGEORDER_ID){|v,w| edges.push([v,w])}
+    assert_equal [['A','B'],['C','D']], edges
+    edges = []
+    graph.each_edge_eid(IGraph::EDGEORDER_ID){|v| edges.push(v)}
+    assert_equal [0,1], edges    
+  end
+
+  def test_enumerable
+    graph = IGraph.new(['A','B','C','D'],true)
+    assert graph.all?{|v| v.kind_of? String}
+    assert graph.any?{|v| v == 'B'}
+    assert_equal ['A','B','C','D'], graph.collect{|v| v}
+    assert graph.detect(Proc.new{true}){|v| }
+    assert_equal ['A'], graph.find_all{|v| v  < 'B'}
+  end
+
+end
diff --git a/test/tc_selectors.rb b/test/tc_selectors.rb
new file mode 100644
index 0000000..3510e42
--- /dev/null
+++ b/test/tc_selectors.rb
@@ -0,0 +1,14 @@
+require 'test/unit'
+require 'igraph'
+
+class TestGraph < Test::Unit::TestCase
+  def test_select_all
+    graph = IGraph.new(['A','B','C','D'],true)
+    assert_equal ['A','B','C','D'], graph.all_vertices
+    assert_equal ['A','B','C','D'], graph.vertices
+  end
+  def test_adj
+    graph = IGraph.new(['A','B','C','D'],true)
+    assert_equal ['B'], graph.adjacent_vertices('A',IGraph::ALL)
+  end
+end